KCSAN: data-race in __inet_hash_connect / inet_send

KCSAN: data-race in __inet_hash_connect / inet_send_prepare (2)
Status: auto-closed as invalid on 2020/11/12 23:57
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 348d, last: 348d

similar bugs (3):
Kernel	Title	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in __inet_hash_connect / inet_send_prepare	2	624d	660d	0/22	auto-closed as invalid on 2020/03/17 07:16
upstream	KCSAN: data-race in __inet_hash_connect / inet_send_prepare (4)	7	100d	103d	21/22	internal: reported on 2021/06/10 14:00
upstream	KCSAN: data-race in __inet_hash_connect / inet_send_prepare (3)	3	262d	279d	0/22	auto-closed as invalid on 2021/02/06 14:09

Sample crash report:

==================================================================
BUG: KCSAN: data-race in __inet_hash_connect / inet_send_prepare

write to 0xffff88808df1e1ce of 2 bytes by task 1195 on cpu 0:
 inet_bind_hash net/ipv4/inet_hashtables.c:95 [inline]
 __inet_hash_connect+0x6cd/0x850 net/ipv4/inet_hashtables.c:760
 inet6_hash_connect+0x77/0x80 net/ipv6/inet6_hashtables.c:329
 tcp_v6_connect+0xabd/0xd00 net/ipv6/tcp_ipv6.c:311
 __inet_stream_connect+0x5c6/0x6b0 net/ipv4/af_inet.c:661
 tcp_sendmsg_fastopen net/ipv4/tcp.c:1173 [inline]
 tcp_sendmsg_locked+0x20ff/0x2200 net/ipv4/tcp.c:1215
 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1442
 inet6_sendmsg+0x5f/0x80 net/ipv6/af_inet6.c:638
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 __sys_sendto+0x2ae/0x380 net/socket.c:1992
 __do_sys_sendto net/socket.c:2004 [inline]
 __se_sys_sendto net/socket.c:2000 [inline]
 __x64_sys_sendto+0x74/0x90 net/socket.c:2000
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88808df1e1ce of 2 bytes by task 1211 on cpu 1:
 inet_send_prepare+0x21/0x210 net/ipv4/af_inet.c:802
 inet6_sendmsg+0x29/0x80 net/ipv6/af_inet6.c:635
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 __sys_sendto+0x2ae/0x380 net/socket.c:1992
 __do_sys_sendto net/socket.c:2004 [inline]
 __se_sys_sendto net/socket.c:2000 [inline]
 __x64_sys_sendto+0x74/0x90 net/socket.c:2000
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 1211 Comm: syz-executor.4 Not tainted 5.9.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci2-upstream-kcsan-gce	2020/10/08 23:55	upstream	3d006ee42dde	92390980	.config	log	report			info